body{
    padding: 0;
    margin: 0;
    background-color: #f7f7f7;
}
.course-login{
    position: relative;
    width: 350px;
    height: 265px;
    margin: 0 auto;
    margin-top: 100px;
    color: #8692a1;
}
input[type="text"]{
    position: relative;
    width: 240px;
    margin: 0 auto;
}
input[type="password"]{
    position: relative;
    width: 240px;
    margin: 0 auto;
}
input[type="button"]{
    position: relative;
    width: 240px;
    margin-left: 40px;
}